1. Field of Use
The present teachings relate generally to coating materials for electrophotographic devices and processes and, more particularly, to coating materials that contain aerogel fillers for providing controllable image gloss levels.
2. Background
Electrophotographic marking is performed by exposing a light image representation of a desired document onto a substantially uniformly charged photoreceptor. In response to that light image, the photoreceptor discharges to create an electrostatic latent image of the desired document on the photoreceptor's surface. Toner particles are then deposited onto that latent image to form a toner image. That toner image is then transferred from the photoreceptor onto a print medium such as a sheet of paper. The transferred toner image is then fused to the print medium, usually using heat and/or pressure.
Gloss is a property of a surface that relates to specular reflection. Specular reflection is a sharply defined light beam resulting from reflection off a smooth, uniform surface. Gloss follows the law of reflection which states that when a ray of light reflects off a surface, the angle of incidence is equal to the angle of reflection. Gloss properties are generally measured in gardner gloss units (ggu) by a gloss meter.
Currently, there is a need to provide options for the level of gloss on prints. Changing the fuser speed or fuser roll temperature can provide only a narrow range of gloss levels, and adding extra hardware to machines (e.g. dual fusers) is expensive. The approach to adjust print gloss by varying the molecular weight of the resins in toner materials is also time consuming and expensive. Changing toner may be convenient for some customers, but inconvenient for some customers requiring frequent changes in gloss setting.
Customers can also purchase additional equipment and apply a varnish/overcoat across the print. Different gloss levels for varnish are available to achieve this varying gloss for different print runs. The additional piece of equipment is costly.
It would be desirable to provide a method of controlling gloss that avoids changing fuser roll speeds, fuser temperature or toner or providing an additional piece of equipment.